Soft top air cleaner assembly

ABSTRACT

A RUBBER SHEET PERFORMED INTO A CONVEX SHAPE IS USED AS THE CENTER PORTION OF AN AIR CLEANER COVER. THE SHEET DUCTS AIR FROM THE FILTER ELEMENT TO THE CARBURETOR INTAKE AND RETAINS ITS SHAPE UNDER ENGINE VACUUM TRANSMITTED THROUGH THE CARBURETOR BUT DEFLECTS UPON ANY CONTACT WITH THE VEHICLE HOOD.

Feb. 16, 1971 D. c. WHEATLEY SOFT TOP AIR CLEANER ASSEMBLY Filed Oct. 25, 1968 ATTORNEYS United States Patent 3,563,010 SOFT TOP AIR CLEANER ASSEMBLY Donald G. Wheatley, Livonia, Mich., assignor to Ford Motor Company, Dearborn, Mich., a corporation of Delaware Filed Oct. 25, 1968, Ser. No. 770,476 Int. Cl. B01d 27/08 U.S. Cl. 55-510 5 Claims ABSTRACT OF THE DISCLOSURE A rubber sheet preformed into a convex shape is used as the center portion of an air cleaner cover. The sheet ducts air from the filter element to the carburetor intake and retains its shape under engine vacuum transmitted through the carburetor but deflects upon any contact with the vehicle hood.

SUMMARY OF THE INVENTION Air cleaners for removing particles from the air entering the carburetors of internal combustion engines traditionally have been made entirely of sheet metal or rigid polymeric materials such as phenolic resins. During vehicle operation, the internal combustion engine moves relative to the vehicle body because of the reaction to the engine generated torque, engine vibration, and road disturbances. Contact between the rigid air cleaner assembly and the vehicle hood must be avoided since such contact could damage the air cleaner body and cover, disturb fuel delivery through the sensitive carburetor fuel jets and passages, transmit engine noise and vibration to the hood, dent the vehicle hood or crack the carburetor housing.

Because of these severe consequences, vehicle designers have provided sufficient clearance to avoid contact between the air cleaner and the vehicle hood during all phases of vehicle assembly and operation including the surprisingly severe conditions encountered when the hood is closed. The necessity of such clearances has limited introduction of new design concepts involving lower vehicle hood lines.

This invention provides an air cleaner assembly capable of absorbing frequent contacts between the air cleaner assembly and the vehicle hood and thereby permitting significant reductions in the design clearance between the air cleaner and the hood. Under normal circumstances the air cleaner assembly of this invention does not contact the hood so noise and vibration transmission and stresses induced thereby are not transmitted to the hood. The air cleaner assembly has a conventional relatively rigid body with a filter element mounted therein. A cover mounted on the body is made up of a relatively rigid peripheral portion that clamps the filter element onto the body and a normally convex flexible central portion that guides air flowing from the filter element into the carburetor induction passage. The flexible central portion is sufliciently strong to retain its shape under engine manifold vacuum transmitted through the carburetor passage but deforms inward when contacted by any exterior member such as the vehicle hood. Forces generated during such contact are absorbed by deflection of the central portion, which returns to its original shape when the deflecting member moves away.

The central portion must continue to conduct air to the carburetor intake while deflected, and it therefore is desirable to increase its resistance to deflection beyond a certain point. Structure capable of this function is provided by running narrow strips of the relatively rigid peripheral portion through the central portion beneath a preformed covering of flexible material. Such strips also provide structural integrity to the top and permit fastening the air cleaner assembly to the carburetor by a threaded fastener passing through its center. Four such strips meeting in the center at approximately right angles usually are sufficient. Air from the filter element normally flows to the carburetor inlet on both sides of the strips. Deflection of the flexible material beyond the strips of course requires considerably more force than that necessary to reach the strips, which occurs only under the most severe circumstances.

Both the air cleaner body and the peripheral portion of the cover can be made of metal in the conventional manner. The filter element is mounted in a lowered position where at least half of the element is below the carburetor inlet. A spacer can be connected to the intersecting portion of the strips to locate the strips a pre determined distance above the carburetor. A threaded fastener projecting through the flexible material, the strips and the spacer then can be used to fasten the air cleaner assembly to the carburetor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectioned elevation view of an air cleaner assembly of this invention showing the lowered position of the filter element relative to the carburetor inlet and the preformed flexible material above the stiffening strips. FIG. 2 is a plan view of the bottom of the cover showing the configuration of the strips and the spacer connected to the intersection of the strips.

DETAILED DESCRIPTION The body of the air cleaner assembly of this invention is represented by numeral 10 in FIG. 1. Body 10 comprises a substantially cylindrical outer wall 12 having an air inlet opening 14 in at least one location. Wall 12 is folded at its upper edge to form a flat ledge 16. The floor of the body projects radially inward from wall 12 for a short distance and then curves upwardly in an extended S- curve 18 to a mounting ledge 20 that defines a substantially circular opening. Ledge 20 is located vertically at or above the midpoint of outer wall 12 and seats on a gasket 22 positioned on a carburetor housing 24. Body 10 usually is made entirely of sheet metal.

Carburetor housing 24 projects upward a short distance above the mounted location of ledge 20 in a thin walled inlet section designated by numeral 26. The air induction inlet 28 formed in inlet section 26 is low at the front and rises as it moves toward the center portion of the carburetor with a diametrical wall 30 defining the rearward portion thereof. A cylindrical boss 32 is formed in wall 30 and contains internal screw threads (not shown). The carburetor choke blade normally mounted in inlet section 26 has been removed from the figure for clarity.

Referring to FIGS. 1 and 2, the cover 34 of the air cleaner assembly has a metal peripheral portion 36 defining an open central portion 38. Two ribs 40 and 42 of the metal peripheral portion 36 extend through central portion 38 and intersect each other at angles in a centrally located hub 44. Pressed into hub 44 from its lower side is a short cylindrical spacer 45. A groove is formed in the outer edge of the cover and a seal 46 located in the groove bears on ledge 16 when the cover is assembled to the body. A conventional filter element 48 is held in place between peripheral portion 36 and the floor of body 10.

A circular flexible member 50 is premolded from a polymeric sheet into a convex shape with the center part recessed as at 51. The outer edge 52 of member 50 is bonded to the top surface adjacent the inner edge of peripheral portion 36. From edge 52, member 50 slopes upward until it approaches the central hub 44 where it turns downward to form a flat circular portion 54. A metal washer 55 is molded or bonded to portion 54 and a threaded fastener 56 passes through washer 55, hub 44 and spacer 45 to engage the threads formed in boss 32.

During engine operation, air enters the air cleaner as sembly through opening 14 and passes through filter element 48. Member 50 guides air leaving the filter element into the carburetor inlet 28. If engine movement relative to the vehicle brings the engine hood into contact with the air cleaner assembly, member 50 deflects to absorb the interference while continuing to direct air to the carburetor inlet. Large amounts of deflection bring member 50 into contact with ribs 40 and 42 which increase the deflection resistance and thus permit air to continue to reach the carburetor inlet. Spacer 45 locates the ribs a sufficient distance above the carburetor inlet to permit air flow to the carburetor even though member 50 has deflected to the ribs.

Flexible member '50 can be made from any polymeric material such as a polycarbonate, polyamide, or the various rubbers. A polycarbonate about 0.040 inch thick, and a butyl rubber having a durometer of about 90 and a thickness of about 0.200 inch have been used successfully. The material is formed so its highest point is about 0.5 inch above the head of fastener 56. Deflection of flexible member 50 normally results from engine pivoting alone or combined with movement in a vertical plane that brings the highest points and the area radially outward thereof into contact with the vehicle hood. Fastener 56 is pivoted away from the hood under these conditions.

Thus this invention provides an air cleaner assembly that permits lowering the hood to a position where intermittent contact between the hood and the air cleaner might occur. Any such contact is absorbed by the flexible material making up the center portion of the air cleaner without transmitting excessive forces between the components.

' What is claimed is:

1. An air cleaner assembly for removing particles from the air entering the carburetor of an internal combustion engine, said assembly having a relatively rigid tray including an inlet for admitting air, a filter element for filtering the air, an outlet for conducting the air to the engine, said filter element filtering the air passing from the inlet to the outlet and a cover mounted on said tray, said cover comprising a relatively rigid annular peripheral portion and a central circular portion covered by a flexible resilient polymeric material, said flexible polymeric material normally having a convex shape extending to a greater height than said peripheral portion but being capable of deforming inward when contacted by an exterior member and returning substantially to its original shape when the deforming force is removed, means securing said cover to said tray, said central portion comprising spaced narrow strips of the material of the peripheral portion extending beneath said flexible material, said flexible material being spaced above said strips and contacting said strips when deflected extensively and said strips increasing the resistance to further deflection.

2. The'air cleaner assembly of claim 1 in which the flexible material is a sheet of polymeric material, said sheet being bonded to the peripheral portion of the cover.

3. The air cleaner assembly of claim 1 in which at least two of said strips intersect each other beneath the center of the flexible material and comprising a spacer means fastened to at least one of said strips for spacing the strips a predetermined distance above the carburetor.

4. The air cleaner assembly of claim 3 in which the spacer means is located at the approximate center of the cover and a threaded fastener projects through the flexible material and the spacer means, said fastener means being capable of threadably engaging the carburetor to fasten the air cleaner assembly thereto.

5. The air cleaner assembly of claim 4 in which the flexible material is a sheet of polymeric material, said sheet being bonded to the peripheral portion of the cover.

References Cited UNITED STATES PATENTS 1,215,974 2/1917 Orem 510 2,579,845 12/1951 MCWherter 220-245 2,904,129 9/1959 McMichael 55276 3,076,555 2/1963 Jackson et al. 2l0493 3,115,276 12/1963 Whitman 220-245 3,160,488 12/1964 Wilber 55501 3,308,608 3/1967 Brimberg 55276 3,339,533 9/1967 Nordstrom 55521 3,355,863 12/1967 Pittsley 55510 3,473,301 10/1969 Buckman 55--5 10 FOREIGN PATENTS 1,147,736 6/1957 France 55510 FRANK W. LU'ITER, Primary Examiner B. NOZICK, Assistant Examiner 

